In several situations of modern life, humans find themselves encountered with the problem of quickly negotiating their way in complex-structured environments such as huge buildings or densely cropped cities. The same holds for the automatic guiding of machines. Apart from traditional approaches for navigation such as printed maps, verbal directions, signs or colour-coded lines painted on the walls or floors of large buildings, radio-based systems have gained recent industrial interest. Among these systems, especially the satellite-based systems such as the Global Positioning System (and the future Galileo system) can be deployed to provide users with position information and, in combination with dedicated navigation devices, also with directions towards a desired target.
However, satellite-based systems in general break down in indoor environments, because the line-of-sight connection to the satellite transmitters is heavily attenuated by concrete ceilings. Furthermore, the spatial resolution of these positioning systems may not be sufficient for navigation in small-scale scenarios.
U.S. Pat. No. 6,049,745 discloses a different approach for navigating automatic guided vehicles (AGVs) through a workplace scenario. A guidance apparatus, e.g. a wire guidance system embedded into the floor, serves as a basic orientation line for the AGV to travel along. Furthermore, Radio Frequency (RF) tags are provided along the guidance apparatus, where each tag is capable of conveying at least one of a plurality of unique RF signals in response to electromagnetic excitation fields. A controller on the AGV is then responsive to these RF signals and, upon reception of an RF signal, initiates a predetermined action of the AGV, such as for instance stopping, turning or honking. The navigation system disclosed in U.S. Pat. No. 6,049,745 is suited to control the traffic of several AGVs moving on prescribed routes through a navigation area. Changing the route of an AGV requires re-programming the RF signals produced by the RF tags and modification of the guidance apparatus. A flexible navigation of AGVs to changing targets is thus not possible.
In view of the above-mentioned problems, it is thus the object of the invention to provide a method and system for accurate and flexible navigating in various types of navigation scenarios.
To solve the object of the invention, it is proposed that a method for navigating within a navigation area, wherein a plurality of navigation tags have been mounted at predetermined positions within the navigation area, is characterised in that it comprises the steps of determining a sequence of navigation tags, which are associated with a desired route within the navigation area, based on said positions of the navigation tags and on topographic information on the navigation area, and navigating said route by passing navigation tags of said sequence of navigation tags, whereby passing of a navigation tag is acknowledged.
When a route, which comprises a start point and an end point and, where appropriate, one or more intermediate points, is defined by a user, the first navigation tag, the position of which is closest to the position of the start point is identified and then represents the first navigation tag in said sequence of navigation tags. Based on an intelligent routing method, then the route to the end point via the intermediate points is determined, where the navigation tags the position of which has the smallest Euclidean distance to this route or the navigation tags that are located at points of the route where a change of direction is necessary, are consecutively entered into said sequence of navigation tags. The user then, tag by tag, processes the sequence of navigation tags by physically passing each navigation tag. The passing of a navigation tag is acknowledged, and each acknowledged tag may be erased from the sequence, until the end point of the route is reached. Each entry in the sequence of navigation tags at least contains any kind of identification of the navigation tag, e.g. a number, a position or a colour code, so that passing of each navigation tag can be uniquely acknowledged. Further information on how to reach the next navigation tag may be included in each entry of the sequence of navigation tags as well, e.g. the direction or distance to the next navigation tag. Instead of navigating said route tag-by-tag, it is also possible to skip navigation tags, i.e. not necessarily all navigation tags of said sequence of navigation tags have to be consecutively passed. Skipping of navigation tags (roaming of the user) may for instance be noticed when passing of the next navigation tag is acknowledged.
A first preferred embodiment of a method of the present invention is characterised in that said positions are stored in a mobile navigation unit, that said mobile navigation unit further stores topographic information on the navigation area and that said sequence of navigation tags is determined by said mobile navigation unit based on said stored positions and said topographic information.
A second preferred embodiment of a method of the present invention is characterised in that said positions are stored in a host unit, that said host unit further stores topographic information on the navigation area, that said stored positions and topographic information are transferred to and stored in a mobile navigation unit, and that said sequence of navigation tags is determined by said mobile navigation unit based on said stored positions and said topographic information.
According to the second preferred embodiment of a method of the invention, said transfer of the stored positions and topographic information may be performed by means of a wired link between host unit and mobile navigation unit or by means of a wireless link.
A third preferred embodiment of a method of the present invention is characterised in that said positions are stored in a host unit, that said host unit further stores topographic information on the navigation area, that said sequence of navigation tags is determined by said host unit based on said stored positions and said topographic information, and that said sequence of navigation tags is transferred to a mobile-navigation unit from the host unit.
According to the third preferred embodiment of a method of the invention, said sequence of navigation tags may be transferred to said mobile navigation unit from said host unit at once, or in parts, whereby transfer of each part of said sequence of navigation tags is initiated by said acknowledgement of the passing of a navigation tag. In the first case, said sequence of navigation tags is also stored in the mobile navigation unit upon receipt, whereas in the second case, storage of each part of the sequence of navigation tags may be optional.
According to the third preferred embodiment of a method of the invention, said transfer of the sequence of navigation tags may be performed by means of a wired link between host unit and mobile navigation unit or by means of a wireless link.
According to the methods of the present invention, it is advantageous that said mobile navigation unit is capable of indicating information on the navigation tag that should be passed next.
Information on the navigation tag that should be passed next advantageously comprises the direction and/or distance to the next navigation tag, and/or an identifier of the next navigation tag.
Said identifier may be a colour and/or a number and/or a symbol.
Said information on the navigation tag that should be passed next is preferably indicated optically and/or acoustically and/or haptically.
According to the methods of the present invention, said acknowledgement of the passing of a navigation tag may be performed automatically or manually and may update said indication of the information on the navigation tag that should be passed next.
An automatic acknowledgement may be based on a wireless link between mobile navigation unit and navigation tag, such as a radio or optic link.
A manual acknowledgement may be based on a wired connection between mobile navigation unit and navigation tag, or by interaction between the user of the mobile navigation unit and the mobile navigation unit.
According to the methods of the present invention, it is further advantageous that the navigation tag itself is capable of storing information and that said information is transferred to said mobile navigation unit when the navigation tag is passed.
Such information may comprise the position of the navigation tag and/or information on the location within the navigation area where the navigation tag is mounted.
According to the methods of the present invention, the position of the navigation tags are preferably determined by means of a terrestrial or satellite-based positioning system such as the Global Positioning System (GPS) and/or by maps and/or plans of the navigation area.
The mobile navigation unit may be integrated into or compatible to a mobile device such as a mobile phone, a personal digital assistant or a GPS receiver.
According to the second preferred embodiment of a method of the invention, it is advantageous that the mobile navigation unit is integrated into or compatible to a mobile phone associated with a mobile radio system, that the core network of the mobile radio system can gain access to said host system, and that said stored positions and topographic information is transferred to the mobile navigation unit via the air interface of the mobile radio system.
According to the third preferred embodiment of a method of the invention, it is advantageous that the mobile navigation unit is integrated into or compatible to a mobile phone associated with a mobile radio system, that the core network of the mobile radio system can gain access to said host system, and that said sequence of navigation tags is transferred to the mobile navigation unit via the air interface of the mobile radio system.
The object of the invention is further solved by a system for navigating in a navigation area, wherein a plurality of navigation tags have been mounted at predetermined positions within said navigation area, characterised in that the system comprises means for determining a sequence of navigation tags, which are associated with a desired route within the navigation area, based on said positions of the navigation tags and on topographic information on the navigation area; and means for acknowledging the passing of a navigation tag, when said route is navigated by passing navigation tags of said sequence of navigation tags.
A first preferred embodiment of a system of the present invention is characterised in that said positions are stored in a storage unit that is comprised in a mobile navigation unit, that said mobile unit further comprises a storage unit with topographic information on the navigation area and that said mobile navigation unit further comprises means for determining the sequence of navigation tags based on the contents of both storage units.
A second preferred embodiment of a system of the present invention is characterised in that said positions are stored in a host unit, that said host unit further comprises a storage unit with topographic information on the navigation area, that said host unit and a mobile navigation unit comprise means for transferring said stored positions and topographic information from the host unit to the mobile navigation unit, that said mobile navigation unit further comprises means for storing said positions and topographic information, and and that said mobile navigation unit further comprises means for determining the sequence of navigation tags based on said stored positions and said stored topographic information.
According to the second preferred embodiment of a system of the present invention, said means for transferring said stored positions and topographic information are advantageously capable of establishing a wired link between host unit and mobile navigation unit or a wireless link.
A third preferred embodiment of a system of the present invention is characterised in that said positions are stored in a storage unit that is comprised in a host unit, that said host unit further comprises a storage unit with topographic information on the navigation area, that said host unit further comprises means for determining the sequence of navigation tags based on the contents of both storage units, and that said host unit and said mobile navigation unit comprise means for transferring said sequence of navigation tags from the host unit to the mobile navigation unit.
According to the third preferred embodiment of a system of the present invention, said means for transferring said sequence of navigation tags are advantageously capable of establishing a wired link between host unit and mobile navigation unit or a wireless link.
Said mobile navigation unit preferably comprises means for indicating information on the navigation tag that should be passed next.
Said means for indicating information on the navigation tag that should be passed next advantageously comprises optic and/or acoustic and/or haptic means.
It is further preferred that means are provided for automatic or manual acknowledgement of the passing of a navigation tag and that means are provided to update said indication of the information on the navigation tag that should be passed next.
Said automatic acknowledgement is preferably based on a wireless link between mobile navigation unit and navigation tag, such as a radio or optic link.
Said manual acknowledgement is preferably based on a wired connection between mobile navigation unit and navigation tag, or on means enabling an interaction between the user of the mobile navigation unit and the mobile navigation unit.
According to the systems of the present invention, it is further preferred that the navigation tag itself comprises means for storing information and that both navigation tag and mobile navigation unit comprise means for transferring said information from the navigation tag to the mobile navigation unit when the navigation tag is passed.
The mobile navigation unit may be integrated into a mobile device such as a mobile phone, a personal digital assistant or a GPS receiver.
According to the second preferred embodiment of a system of the present invention, it is preferred that the mobile navigation unit is integrated into or compatible to a mobile phone associated with a mobile radio system, that the core network of the mobile radio system can gain access to said host system, and that said stored positions and topographic information are transferred to the mobile navigation unit via the air interface of the mobile radio system.
According to the third preferred embodiment of a system of the present invention, it is preferred that the mobile navigation unit is integrated into or compatible to a mobile phone associated with a mobile radio system, that the core network of the mobile radio system can gain access to said host system, and that said sequence of navigation tags is transferred to the mobile navigation unit via the air interface of the mobile radio system.
Furthermore, the object of the invention is solved by a computer program product directly loadable into the internal memory of a digital computer, comprising software code portions for performing the steps of any of the aforementioned methods according to the present invention when said product is run on a computer.